Common Subsequence
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 26493 Accepted Submission(s): 11771
Problem Description
A subsequence of a given sequence is the given sequence with some elements (possible none) left out. Given a sequence X = <x1, x2, ..., xm> another sequence Z = <z1, z2, ..., zk> is a subsequence of X if there exists a strictly increasing
sequence <i1, i2, ..., ik> of indices of X such that for all j = 1,2,...,k, xij = zj. For example, Z = <a, b, f, c> is a subsequence of X = <a, b, c, f, b, c> with index sequence <1, 2, 4, 6>. Given two sequences X and Y the problem is to find the length of
the maximum-length common subsequence of X and Y.
The program input is from a text file. Each data set in the file contains two strings representing the given sequences. The sequences are separated by any number of white spaces. The input data are correct. For each set of data the program prints on the standard
output the length of the maximum-length common subsequence from the beginning of a separate line.
Sample Input
abcfbc abfcab programming contest abcd mnp
Sample Output
4 2 0
表示好几天 没有a过题目了 ，原因好多，平时课程多死，省赛训练也经常跑西区，做的题目也不再是水题了，主要学习过程挺费时间 ，我相信只要把某个算法学会了，然后
做的类似的题目就不会浪费时间了。 今天五一 也算有了一点点 属于自己的时间，（其实五一还是有好多事情要干）。
参考学习了网上这篇博文，和《算法导论》叙述得差不多，
http://blog.csdn.net/yysdsyl/article/details/4226630
代码敲的少啊 ，连scanf（）语法也卡了好大会儿。不过 以后知道了……
其实我感觉 ｓｔｒｉｎｇ处理字符串 也挺方便。
#include<iostream >
#include<stdio.h>
#include<cstring>
const int M=500;
using namespace std;
int main()
{
char cnt[M],dic[M];
int c[M][M],k,m;
while(scanf("%s%s",cnt+1,dic+1)!=EOF)
{
int lencnt=strlen(cnt+1);
int lendic=strlen(dic+1);
for(int i=1; i<=lencnt; i++)
c[i][0]=0;
for(int j=0; j<=lendic; j++)
c[0][j]=0;
for( k=1; k<=lencnt; k++)
for( m=1; m<=lendic; m++)
{
if(cnt[k]==dic[m])
{
c[k][m]=c[k-1][m-1]+1;
}
else
{
c[k][m]=max(c[k-1][m],c[k][m-1]);
}
}
cout<<c[lencnt][lendic]<<endl;
}
return 0;
}